For Crust: Stir together crumbs, butter, sugar and salt. Press onto bottom and 1 inch up the side of a buttered 9- or 10-inch springform pan. Fill right away or chill crust up to 2 hours.

For Filling: Beat cream cheese with an electric mixer until fluffy. Add eggs, one at a time, then vanilla and sugar, beating on low speed until each ingredient is incorporated, scraping down bowl between additions.

Put springform pan with crust in a shallow baking pan. Pour filling into crust and bake in a baking pan (to catch drips) in middle of oven 45 minutes, or until cake is set 3 inches from edge but center is still slightly wobbly when pan is gently shaken. Let stand in baking pan on a rack 5 minutes. Leave oven on.

For Topping: Stir together sour cream, sugar and vanilla. Drop spoonfuls of topping around edge of cake and spread gently over center, smoothing evenly. Bake cake with topping 10 minutes.

Run a knife around top edge of cake to loosen and cool completely in springform pan on rack. (Cake will continue to set as it cools.) Chill cake, loosely covered, at least 6 hours. Remove side from pan and transfer cake to a plate. Bring to room temperature before serving.